Multiple electrical outlet



Oct. 17, 1961 H. H. HOLT 3,005,179

MULTIPLE ELECTRICAL OUTLET Filed July 28, 1959 2 Sheets-Sheet 1 INVENTOR, Mama/v0 H. 1 /047 Oct. 17, 1961 H. H. HOLT MULTIPLE ELECTRICAL OUTLET 2 Sheets-Sheet 2 Filed July 28, 1959 INVENTOR. Mar/now A! #04 BY /T7'0,A/V

Un d Secs t -MULTIPLE ELECTRICAL OUTLET Hammond H. Holt, Sherman Oaks, Califi, assignor, by mesne assignments, to Brl-Son Electronics, Inc., Los Angeles, Calif., a corporation of California Filed July 28, 1959, Ser. No. 830,140 6 Claims. (Cl. 339-159) This invention relates to multiple electrical outlet plug units, and particularly to such a plug unit which may be used as a single multiple unit, a pair of which may be combined separately or integrally to double the number of outlets.

Multiple electrical outlet plugs of different types are well known, the present invention having a new construction providing economy in manufacture, increased rehability, and greater efiiciency in the conservation of space. Instead of two symmetrical sections abutting one another which depend upon'the metal contact springs or pins to prevent rotation with-respect to one another, the symmetrical sections of the plug to be descnbed'm detail hereinafter interlock with oneanother to prevent rotation and, thus, form a particularly rugged, integral unit. Each spring contact ha's'its own receptacle, housing or cavity,

which isolates it from the other spring contacts and which prevents strain among thecontact elements and: reduces the possibility of short circuits'within the outlet plug Another feature is that the construction is symmetrical not only as to the interlocking sections but along-a center line of a six-outlet unit, which permits two three-outlet units to be combined to form a six-outletunitif an integral six-outlet unit is not desired. The unit may be assembled without riveting'or the use of'similar fastening means.

The principal object of the invention, therefore, is to facilitate the connection of multiple load devices to a single wall or line outlet.

Another object of the invention is to provide an improved multiple electrical outlet which requires a minimum of space with optimum safety and reliability.

A further object of the invention is to provide an improved multiple electrical outlet plug which has interlock identical sections for economy in manufacture and which may be constructed as a single multiple unit or a double multiple unit.

A better understanding of this invention may be had from the following detailed description when read in connection with the accompanying drawings, in which:

FIG. 1 is a perspective view of a six-outlet integral multiple electrical plug unit embodying the invention;

FIG. 2 is a side view of the unit shown in FIG. 1;

FIG. 3 is a plan view of one section of the unit shown in FIG. 1;

FIG. 4 is a plan view of the other section of the unit shown in FIG. 1;

FIG. 5 is a cross-sectional view taken along the line 55 of FIG. 1;

FIG. 6 is a perspective view of two of the electrical contact spring assemblies; and

FIG. 7 is a perspective view of a single multiple plug unit embodying the invention.

Referring, now, to the drawings in which the same reference numerals identify the same elements, the sixoutlet unit shown in FIGS. 1 through 6 has two identical sections 5 and 6 in which are screw holes 7 and 8 showing that screws may be used for fastening the sections 5 and 6 together although these sections may be held to gether by friction, glue, or other suitable means. A standard decorative plate 12 of plastic or metal may be attached to the unit by the screws holding the unit sections together. In FIG. 2, the unit is shown partially inserted in a double wall outlet shown by dotted lines 10, and two load connectors are shown at 3 and 4 in FIG. 1.

Referring, now, to FIGS. 3 and 4 showing the details of construction of the two identical sections 5 and 6, in diametric corners of section 5 are partitions or walls 15 and 16 in the form of a square block on plate 17, and in diametric corners of section 6 are partitions or walls 19 and 20 in the form of a square block on plate 21. The plates and walls of sections 5 and 6 may be of plastic or similar material, and their construction is such that they may be easily molded. These partitions are of the height shown in FIGS. 1 and 2, which is the height of the spring cavity walls and cavity closing tabs.

Six spring contact cavities are shown in each section 5 and 6, end cavities 23 and 24 being formed in part by one of the walls of blocks 15 and 16, respectively, and walls 25 and 26, respectively. Cavities 28 and 29 of section 6 are formed in part by the walls 30 and 31 and a wall of blocks 19 and 20, respectively. The side cavities 33, 34, 35, and 36 in section 5 are formed in part by walls 38 and 39 for cavity 33, walls 40 and 41 for cavity 34, walls 42 and 43 for cavity 35, and walls 44 and 45 for cavity 36. In section 6, the side cavities 47, 48, 49, and are formed in part by walls 52 and 53 for cavity 47, walls 54 and 55 for cavity 48, walls 56 and 57 for cavity 49, and walls 58 and 59 for cavity 50.

To further close these spring contact cavities, a plurality of small tab walls or ribs are provided. On plate 17 is tab wall 61 which when sections 5 and 6 are com bined-by folding the two sections on one another, closes an end of cavity 28 as shown by dotted lines 62. A corresponding tab wall 64 on plate 21 closes an end of cavity 23 as shown by dotted lines 65. At the other ends of sections 5 and 6, a tab wall 63 on plate 21 closes an end of cavity 24 as shown by dotted lines 66, while the tab wall 67 on plate 17 closes an end of cavity 29 as shown by dotted lines 68.

With respect to cavity 48 on plate 21, an end thereof is closed by tab wall 69 on plate 17 as shown by dotted lines 70. To close an end of cavity 34 on plate 17, tab Wall 72 on plate 21 is used as shown by dotted lines 73. Likewise, for cavity 35 on plate 17, tab wall 74 on plate 21 is used as shown by dotted lines '75, and for cavity 49, tab wall 77 is used as shown by dotted lines 78. For cavity 36, tab wall 79 is used as shown by dotted lines 80, while for cavity 50, tab wall 82 is used as shown by dotted lines 83. For cavity 33, tab wall 71 on plate 21 is used as shown by dotted lines 76 on plate 17, while for cavity 47, tab wall 84 on plate 17 is used as shown by dotted lines 46.

The other ends of the cavities are open. to permit the entry of the prongs of the connectors of the load cords, it being noted each entry end is tapered to hold the ends of the spring contacts, the ends of the spring contacts being slightly spaced from the inside surfaces of the cavity walls to permit easy separation thereof to accommodate the prongs of the connectors.

Referring, now, to FIGS. 5 and 6, the unit 85 has three spring contacts 86, 87, and 88 and along prong 89, while unit 90 has spring contacts 91, 92, and 93 and a shorter prong 94. The unit 90* is shown in the upper portion of section 5 in FIG. 3, this unit being a flat, conducting metal, such as copper, interconnecting the three spring contacts, the shorter prong 94 passing through plate 17. The unit 85 is shown in the upper portion of section 6 of FIG. 4 with the long prong 89 extending upwardly from the paper. This prong will pass through slot 96 in plate 17 when the two sections are combined. Two units similar to units 85 and 90 are used at 97 and 98, the short prong being at 100 and the long prong at 102, respectively.

Slot 103 accommodates the long prong 102. These spring contact units need only be placed in position as shown in FIGS. 3 and 4, and no rivets, screws, or other means are required to'fasten them to the plates 17 and 2 1.

- The above-described multiple plug unit will suflice for six outlets in the minimum of space from the face of the wall outlet, and Will be entirely enclosed with parallel spring contacts isolated from one another for safety. Since sections 5' and 6- are identi-cfl, the manufacturing cost of the plug is reduced, While the prong units 85 and hi? are practically the same. The unit is rapidly assembled since the sections can be held together by any suitable means. Although the sections 5 and 6 can be folded over one another, as mentioned above, section 5 could be rotated 180 degrees and placed on section 6 since the sections are symmetrical along both horizontal and vertical center lines.

Referring, now, to FIG. 7, a single multiple unit is shown in which only three outlets are provided with only two prongs. This is exactly one-halt of the unit shown in FIG. 1 and is composed of a plate 105 with a cover plate 111, a duplicae reverse plate 196 with prongs 197, which may be held together with a screw in hole 110. Parallel outlets slots are shown at 108 and 169', the third slot being on another edge of the unit. Since corner blocks and-19 are not used, a wall 112 along the center line to close the fourth edge will have one-half on each plate Hi5 and 18:6. However, the unit shown in HQ. 7 could be exactly one-half of the unit shown in FIG. 1 and two of such single multiple units could be combined to form the double multiple unit.

Iclaim: v v

1. A multiple electrical contact plug comprising a pair of rectangular substantially identical and parallel spaced plates, said plates having wall and partition members extending at right angles therefrom to form an outside edge enclosure having a plurality of pairs of edge openings on each edge thereof when said plates, wall and partition members are joined together, certain of said well members forming internal cavities with said edge openings therein, multiple spring contact units mounted in said certain cavities having said edge openings therein, and a pair of prongs connected to said units and extending through one of said plates, said plates having tab wall elements for substantially closing said cavities except for said edge openings thereto, the tab wall elements on one plate substantially closing the cavities on the other plate.

2. multiple electrical contact plug in accordance with claim 1 in which each half of each plate is identical tothe other half thereof when each plate is rotated 180 degrees on its central axis.

3. A multiple electrical contact plug adapted to occupy a minimum of space from a wall outlet comprising a pair of sections having plates and walls extending perpendicularly from said plates, certain of said walls forming rectangular cavities having internal open ends and exterior edge openings, a contact spring unit in each of saidcavities, certain of said spring contact units being interconnected in each section, a plurality of narrow tab walls mounted on one of said sections and adapted to close the internal open endsof the cavities in the opposite section when said' sections are folded together, certain other of said walls forming the outside edge closure for said plug between. said cavities 4. A multiple electrical contact plug comprising a pair of substantially identical and parallel spaced plates, perpendicular edge and internally-positioned walls on said plates, some of. said walls forming a closing wallrfor said plug'and other-ofsaid walls forming cavities having openings in the edges of said plug, each plate and its walls forming a section which is a-reverse duplicate of the other section so that said sections may be folded together, .said plates being separated by the height of said walls, and tab walls on said plates for substantially closing said cavities, the tab'walls attached to one plate sub-- stantially closing the cavities on-the other plate, and a. plurality of groups of electrical spring contacts, said spring contacts being positioned in said cavities, and certainof said spring contacts being interconnected physically and electrically.

5. A multiple electrical contact plug in accordance with claim 4 in which said sections arerectangular, and two groups of three spring contacts are provided in each section.

, 6. .A multiple electrical contact plug in accordance with claim 4rin which'said spring contacts are'U-shaped, the

legs thereof contacting at thecentral portions thereof, a flat, conducting strip positioned on a respective plate interconnectingthree of said spring contacts.

References Cited in the file of this patent UNITED STATES PATENTS Great Britain Dec. K10, 1952 

